Unauthorized entry indicator and method

ABSTRACT

A preferred apparatus for practicing the method comprises silicon controlled rectifiers with anode gate triggering incorporated in a two mode alarm device that can be attached to the inside of a door. Audible mode indicates by the emittance of a penetrating sound perceived by someone on the inside of the door that it is being opened. Radio frequency mode indicates by the absence of a signal, received on a portable radio outside the door, that the door was opened after the mode switch was locked and left.

United States Patent Smith 1451 Apr. 11, 1972 [54] UNAUTHORIZED ENTRYINDICATOR 3,304,547 2/1967 Bristol ..340/276 x AND METHOD 3,449,7386/1969 Chesnul et al ..340/276 x 3,493,967 2/l970 Ressler ..340/276 Xlnvenwrr Lyle Douglas Smnh, 3400 Carlyn Sprmg 3,537,094 10/1970 Hawkinset al ..340/276 x Road, Falls Church, Va. 22041 Primary Examiner-John W.Caldwell [22] Filed. Jan. 1970 Assistant Examiner-William M. Wannislty[21] Appl. N0.: 2,519 Att0rney-Wilfred G. Caldwell [52] U.S. Cl..340/274, 340/274, 340/276, [57] ABSTRACT 340/327 A preferred apparatusfor practicing the method comprises sil- 511 1111.01. ..G08b 13/08 iconcontrolled rectifiers with anode gate triggering 58 Field at Search.340/274, 276, 293, 307, 322, Porated in a two mode alarm device thatcan be attached to 340/324 327; 200 2; 1 16/85, 100 the inside ofa door.Audible mode indicates by the emittance of a penetrating sound perceivedby someone on the inside of [56] References Cited the door that it isbeing opened. Radio frequency mode ir1- dicates by the absence of asignal, received on a portable radio UNITED STATES PATENTS outside thedoor, that the door was opened after the mode l d f 3,487,404 12/1969Midkiff ..340/276 x sw'tch was and let 3,426,348 2/1969 Sadler ..340/276UX 11 Claims, 2 Drawing Figures RADIO 4 SONIC FREOUENCY I FREOUENCYENERGY RFI 51 ENERCY GENERATOR GENERATOR l l l 6'' 1 I F 1 MODE G 1SELECTOR CIRCUIT TO 1 gym 01110111110 TURN OFF l TURN ON RELAY lYHENRELAY DOOR IS YIHENEVER lNlTlALLY DOOR IS OPEN OPENED NANUALLY HELDBISTABLE SWITCH TO RELAY TO ALLOW OPENING TURN SONIC DOOR WITHOUT CEN.ONOR CHANCINC STATE RADIO FRED. OF RELAY GEN. OFF

PATENTEUAPR 11 I972 3, 656, 143

SHEET 1 [1E2 A B RADIO 4 SONIC FREQUENCY I FREOUENCY ENERGY R5, SF 1ENERGY GENERATOR GENERATOR I V G: g I F i MODE G I SELECTOR CIRCUIT TO Isync" CIRCUIT TO TURN OFF TURN ON RELAY NI'IEN RELAY DOOR IS \YNENEVERINITIALLY DOOR IS OPEN OPENED E D NANUALLY HELD BISTABLE SNITCH TO RELAYTO ALLOYY OPENING TURN SONIC DOOR WITHOUT GEN.ON OR CHANGING STATE RADIOFRED. OF RELAY GEN. OFF

INVENTOR F G. I 0

UNAUTHORIZED ENTRY INDICATOR AND METHOD BACKGROUND OF THE INVENTIONSUMMARY OF THE INVENTION The invention shifts emphasis from protectingproperty to protecting tenants from harm by indicating that theapartment has been violated and the intruder may still be present, or isbeing violated and appropriate action must be taken.

This new philosophy enables the design of a device that eliminates thedisadvantages of the conventional alarm. An explanation of the operationof the invention will makethe advantages of the invention clear. Forsimplification, we will assume that the apartment is inaccessible exceptthrough the door. If the tenant is in his apartment and wishesprotection from a sneak intruder, he turns the key operated switch ofthe invention to audible mode and removes the key to any inconspicuouslocation. If there is a knock on the door, the door can be openedwithout triggering the alarm by holding a push button depressed duringthe time the door is opened. If the door is opened without the pushbutton being depressed, a penetrating, but not illegally loud, sound isemitted and cannot be quieted without the key operated switch beingswitched to radio frequency mode. Most intruders will make a rapiddeparture; if not, the tenant is at least forewarned and can takeappropriate action.

To prevent triggering of the audible mode by maintenance or managementpersonnel when the tenant is away, the invention switched to audiblemode will not allow the tenant to leave without triggering. However,after triggering, the key operated switch is immediately switched toradio frequency mode. The tenant has unavoidably tested the inventionand battery condition, and leaves taking the key with him.

Upon returning, the tenant can tell within ten feet of his door if ithas been opened in his absence by listening to any portable radio tunedto the radio frequency of the invention. If he hears the modulatedsignal, he can be certain that his door has not been opened. If he doesnot hear the signal, he should not proceed without checking with theapartment manager to find whether maintenance personnel have been, orare, in his apartment, and then take appropriate action if needed.Assuming the signal is heard, the tenant opens the door and the deviceautomatically and silently turns off.

It should now be apparent that the method and apparatus of thisinvention is applicable to other security locations, such as top-secretrooms or buildings, storage closets, filing cabinets, and the like. Incertain instances, it may be necessary to employ an external antennawhere the device is protecting a particularly well shielded area, suchas a metal file, safe, or vault.

With the foregoing in mind, it is an object of the invention to providea combination sonic frequency-radio frequency (SF-RF) alarm typeindicator. Another object of the invention is the provision of such anapparatus which automatically signals if left in the SF mode, therebyserving to indicate its alarm capabilities, as well as to alert the userto shift the key to the RF'position.

A further object of the invention is the provision of a method primarilyfor protecting a person, as contrasted with prior art methods forprotecting only personal property. A further object of the method is toinsure that the user operates the device properly, and is aware ofitsoperational state.

Yet another object of the invention is to provide a circuit absolutelycapable of minimum power drain although maintaining the apparatuscontinuously in an operational state in one or the other mode, ifdesired. A feature of the invention resides in the fact that the circuitis switched off from the RF mode when the door is opened and at theusers option may be programmed to the SF mode.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a diagram of the operationalcomponents and configuration of the invention and shows graphically therelationship of the component subcircuits, and the implied sequence ofoperation.

FIG. 2 is a schematic of the circuit of the invention and providesreference points for following the written description of the circuit.

DESCRIPTION OF THE PREFERRED EMBODIMENT The method and broad blockdiagram components may best be understood fromthe general arrangement ofFIG. 1. It may be seen that both a remotely detectable source of energyand a locally detectable source of energy are provided. The former ispreferably a Radio Frequency Energy Generator A and the latter a SonicFrequency Energy Generator B. The RF -SF Mode Selector Switch C isprovided for past and present indications. A control relay D (which mayground the circuitry) is shown as the block labeled Bistable Relay toTurn Sonic Generator on or Radio Frequency Generator off and it ispartially under control of a Manually Held Switch E which permitsopening of the door without changing the relay state.

The two blocks F and G may comprise separate windings for operating therelay D, or alternatively, may comprise a single on/off switch foroperating a more sophisticated electronic device capable of thefunctions required in block D. In any event, block F turns off the relaywhen the door is initially opened, thereby disabling the RF generator Aso that the user detects the absence of the RF signal to indicate thatthe door had been opened.

On the other hand, with the circuit in the SF mode, the block G isprovided to turn on relay D, permitting sonic frequency generation at Bwhenever the door is opened and thereafter until a key is used to switchMode Selector Switch C back to the RF position.

The functions and operations of the invention are accomplished bythefollowing circuit. The total circuit of the invention is composed ofvarious subcircuit arrangements. The total circuit is most easilyunderstood if the subcircuits are described separately.

Modulated Radio Frequency Energy Generator Arrangement: Resistor l,capacitor 2, and SCR 3 form a relaxation oscillator whose energy, storedin capacitor 2, is rapidly fired into the tank circuit of inductor 4 andcapacitor 5 causingit to ring at the tuned radio frequency. SCR 3 firesat an audio rate, therefore, giving the effect of a modulated radiofrequency generator. SCR 3 fires because resistor 6 and resistor 7 forma voltage divider that determines the static potential of the anode gate8, the anode 9 potential climbs toward supply voltage and when itexceeds the anode gate 8 potential by about 0.7 volt, SCR 3 fires. Whencapacitor 2 is sufficiently discharged, SCR 3 falls out of conductionbecause resistor 1 cannot provide adequate holding current, and thecycle repeats.

It should also be appreciated that the radio frequency energy sourcecould, with some alteration of the circuit, be changed to an energysource of a different character, such as an ultralow frequency sound tobe detected by a special device or a simple light arrangement that couldbe seen through a window or under the door.

Sonic Frequency Energy Generator Arrangement: Resistor l0, capacitor 11,and SCR 12 form a relaxation oscillator whose energy, stored incapacitor 11, is fired through resistor 13 into the base of transistorl4 causing transistor 14 to discharge a portion of low impedance energystored in capacitor 15 through the speaker l6to ground. Resistor 17, inconjunction with capacitor 15, constitutes a high impedance input to thelight-duty batteries 33 and 34. SCR 12 fires because resistor 18 andresistor 19 form a voltage divider that determines the static potentialof the anode gate 20, the anode 21 potential climbs toward supplyvoltage, and when it exceeds the anode gate 20 potential by about 0.7volt, SCR 12 fires. When capacitor 11 is sufficiently discharged, SCR l2falls out of conduction because resistor cannot provide adequate holdingcurrent, and the cycle repeats.

Mode Selector Arrangement: Key operated switch 22A and 22B selectseither radio frequency 30 mode of operation or sonic frequency 31 modeof operation. These switches may be the same single switch, but areshown separately to simplify the circuit connections.

Turn On Arrangement: Key operated switch 22A provides continuity betweenthe anode gate 23 of SCR 24 and ground through the normally closedmomentary contact push button switch 25, and the normally closed (whenthe door is opened) magnet 26B actuated switch 26A. SCR 24 turns onbecause the anode 27 is more than 0.7 volt higher in potential than theanode gate 23.

Turn Off Arrangement: Resistor 28 provides charging current forcapacitor 29 when SCR 24 is conducting provided key operated switch 22Ais in radio frequency mode position 30, and normally closed momentarycontact push button switch 25, or normally open (when the door isclosed) magnet 26B actuated switch 26A is in an open state. SCR 24 turnsoff when the charged capacitor 29 discharges to ground through normallyclosed momentary contact push button switch 25 and the normally closed(when the door is open) magnet 26B actuated switch 26A, thus, reversebiasing SCR 24 to accomplish turn off.

Remote Actuating Arrangement: The commercially available switch 26Aincludes a spring 35 which will maintain the switch closed in theabsence of magnet 268. It will now be appreciated that the invention maybe used as an indicating device for areas having more than a singleaccess, each of which may require guarding. Thus, as many normally openswitches as may be desired can be connected in parallel with switch 26A,as shown by switch 36, with takeoff leads 37 and 38 provided foradditional switches. Thus, the windows and the doors of a house, forexample, could be used to suppress the RF signal whenever any access isviolated. Similarly, if the device is in the SF mode, the opening of anyclosure would initiate the sonic alarm.

Authorized Entrance Arrangement: The door, activating magnet 26Bactuated switch 26A, may be operated without affecting the turn oncircuit or the turn off circuit provided normally closed momentarycontact push button switch 25 is held open during the open doorcondition.

SCR 24 Maintenance Current Arrangement: Resistor 6, in series withresistor 7, provides unbroken current flow to SCR 24 when the keyoperated switch 22B is being switched from the sonic generator position31 to the radio frequency generator position 30, therefore, preventingunavoidable turn off of SCR 24 during the transition.

Extraneous Noise Suppression Arrangement: Capacitor 32 provides a shortcircuit for noise potentials between the anode 27 and the anode gate 23that could randomly turn on and off SCR 24.

Power Supply Arrangement: Battery 33 and battery 34 are in series toprovide a total of 18 volts supply voltage.

The above described circuit achieves absolute minimal current drain,such that the batteries 33 and 34 may operate the circuit in the RF modefor periods substantially corresponding to their shelf life, and thenthe batteries may be replaced at minimal cost because they areconventional nine volt transistor radio batteries. Also, even if forsome reason the circuitry is left inadvertently in the SF mode, it iscalculated that the alarm would sound for several days. In order toachieve this unusual type of efficient operation, the followingcomponents are used:

Ref. No. of FIG. 2

Manu- Component facturer Stock No. .Value 2 Capacitor 0.005 MFD 3 SCR GED13Tl 4 Inductor Miller 2002 5 Capacitor 230 UUFD 6 Resistor 220K 7Resistor 220K 10 Resistor 47K 11 Capacitor l MFD l2 SCR GE D13T1 l3Resistor 20 14 Transistor Motorola MPS U01 l5 Capacitor 200 MFD 16Speaker Quam 2%" 8 ohm l7 Resistor 500 18 Resistor 1K 19 Resistor 10K 22A/B Switch- Key operated Smith 1038 DPDT 24 SCR GE D13T1 25 SwitchSwitchcraft 103 SPST- 26 All! Switch & magnet combination Alco RS24NCSPST- 28 Resistor l0 MEG 29 Capacitor 2.5 MFD 32 Capacitor 0.1 MFD 33Battery Eveready 216 9 vol! 34 Battery Eveready 216 9 volt 36 SwitchSPST- From the foregoing description, it may be appreciated that thecircuit of FIG. 2 could just as well be arranged to initiatetransmission of the RF frequency when the closure is violated.Similarly, it will be seen that the RF and SF oscillator could comprisea single oscillator which could be tuned to operate in the RF or SFmode. in addition, any violation of the closure in the RF mode couldsignal the local desk in an apartment house or even the local policedepartment over electrical leads in order that the premises could bechecked to determine whether the entry was unauthorized. Naturally, theuser would enter and switch the mode or otherwise disable the remoteactuated alarm signal, but even in the absence of a remote alarm, thedevice positively signals illegal entry or entry by someone other thanthe user and thus eliminates the problem of guessing whether anassailant lies in wait or whether or not the apartment was violatedregardless of whether it was left locked or unlocked.

What is claimed is:

l. The method of signaling present violation of a closure by an intruderduring one period and indicating past violation of said closure during adifferent period comprising the steps of: establishing an off conditionof a first frequency radiation substantially at the beginning of saidone period wherein violation of the closure during said one periodchanges the off condition to an on condition; signalling said oncondition audibly in a manner intended to frighten off said intruder;establishing one of two conditions including the presence and absence ofa different frequency radiation during said one period wherein violationof the closure changes the established condition; and detecting thechanged condition in a predetermined secretive manner to learn of theviolation.

2. The method of claim 1 wherein the one of two conditions areestablished by generating a radio frequency, and wherein said firstfrequency radiation comprises an audio frequency.

3. The method of claim 2 further comprising the step of maintaining theaudio frequency regardless of the condition of the closure.

4. The method of claim 3 comprising the further step of interrelatingthe radio frequency generation and the audio frequency generation torequire first audio frequency generation before enabling of the radiofrequency generation.

5. Apparatus for indicating past violation of a closure by an intrudercomprising in combination switching means actuable by violation of theclosure; means for generating an audible first frequency radiation inresponse to present violation of the closure during the first periodunder control of said switching means; said audible first frequencyradiation being designed to frighten off the intruder; and means forestablishing one of two predetermined conditions not apparent to theintruder including the presence and absence of a different frequencyradiation during a different period; said last mentioned means beingresponsive to the closure switching means to switch its condition uponviolation of the closure.

6 The apparatus of claim 5 wherein the means for generating a firstradiation comprise audio frequency generating means, and the means forestablishing one of two conditions comprise radio frequency generatingmeans.

7. The apparatus of claim 5 further comprising mode selector switchmeans for selectively enabling either the means for generating the firstradiation or the means for establishing one of two conditions.

8. The apparatus of claim 5 wherein the means for generating a firstfrequency radiation and the means for establishing one of two conditionsincludes a common connection; and means for interrupting said commonconnection when a violation occurs during said different period.

9. The apparatus of claim 8 comprising mode selector switch means forenabling either the means for generating the first radiation or themeans for establishing one of two conditions; and means for renderingthe means for interrupting operative to complete the common connectionin response to the mode selector switch means when in the firstradiation generating mode.

10. The apparatus of claim 5 wherein said switching means actuable byviolation of the closure comprises a plurality of switches connected inparallel for respective location at accesses to the closure.

11. Signaling apparatus for guarding a closure'from an intrudercomprising in combination means actuable upon violation of the closure;silent memory means responsive to said actuable means for secretivelyindicating past violation of the closure; and separate audible meansresponsive to said actuable means for indicating present violation ofthe closure in a manner alarmingly different from the past violationindication.

1. The method of signaling present violation of a closure by an intruderduring one period and indicating past violation of said closure during adifferent period comprising the steps of: establishing an off conditionof a first frequency radiation substantially at the beginning of saidone period wherein violation of the closure during said one periodchanges the off condition to an on condition; signalling said oncondition audibly in a manner intended to frighten off said intruder;establishing one of two conditions including the presence and absence ofa different frequency radiation during said one period wherein violationof the closure changes the established condition; and detecting thechanged condition in a predetermined secretive manner to learn of theviolation.
 2. The method of claim 1 wherein the one of two conditionsare established by generating a radio frequency, and wherein said firstfrequency radiation comprises an audio frequency.
 3. The method of claim2 further comprising the step of maintaining the audio frequencyregardless of the condition of the closure.
 4. The method of claim 3comprising the further step of interrelating the radio frequencygeneration and the audio frequency generation to require first audiofrequency generation before enabling of the radio frequency generation.5. Apparatus for indicating past violation of a closure by an intrudercomprising in combination switching means actuable by violation of theclosure; means for generating an audible first frequency radiation inresponse to present violation of the closure during the first periodunder control of said switching means; said audible first frequencyradiation being designed to frighten off the intruder; and means forestablishing one of two predetermined conditions not apparent to theintruder including the presence and absence of a different frequencyradiation during a different period; said last mentioned means beingresponsive to the closure switching means to switch its condition uponviolation of the closure. 6 The apparatus of claim 5 wherein the meansfor generating a first radiation comprise audio frequency generatingmeans, and the means for establishing one of two conditions compriseradio frequency generating means.
 7. The apparatus of claim 5 furthercomprising mode selector switch means for selectively enabling eitherthe means for generating the first radiation or the means forestablishing one of two conditions.
 8. The apparatus of claim 5 whereinthe means for generating a first frequency radiation and the means forestablishing one of two conditions includes a common connection; andmeans for interrupting said common connection when a violation occursduring said different period.
 9. The apparatus of claim 8 comprisingmode selector switch means for enabling either the means for generatingthe first radiation or the means for establishing one of two conditions;and means for rendering the means for interrupting operative to completethe common connection in response to the mode selector switch means whenin the first radiation generating mode.
 10. The apparatus of claim 5wherein said switching means actuable by violation of the closurecomprises a plurality of switches connected in parallel for respectivelocation at accesses to the closure.
 11. Signaling apparatus forguarding a closure from an intruder comprising in combination meansactuable upon violation of the closure; silent memory means responsiveto said actuable means for secretively indicating past violation of theclosure; and separate audible means responsive to said actuable meansfor indicating present violation of the closure in a manner alarminglydifferent from the past violation indication.